and i agree. its hard to tell if any differences were real or imagined since i went from used oil to atf. then from burned atf to oil again. i think the only way to really test it would be to run fresh 10/30 for say 30 miles, then swap it for ATF (filling it, then draining it, then refilling it again to remove as much oil as possible for a fair test) and compare them both on the same day.

ive thought about using the amsoil atf. post back after you've ran it a while. if it lasts longer i might give it a whirl. i seem to change the 10/30 whenever i change the plug (4-500 miles or so)

the 60cc upgrade i described earlier is cheap and works extremely well. since they built the YT60's around it i dont see how it will lower the lifespan noticibly either. and even if it does new engines are cheap too. which is why i know nothing about porting and all that for a QT50. so unless you just want to do it to experament or some other specific reason, i would recommend against it.

Hi, I also have a 1984 QT50 that runs good but will not go over 25 MPH with the similar symptoms mentioned here. I am going to try the general upgrades posted here and see what happens. I assume you guys are drilling the airbox on the rear half of the cover and not the front? 3-4 1/4'' holes?